1. Field of the Disclosed Embodiments
This disclosure relates to systems and methods to facilitate spectrum management for wireless networks that may employ spectrum allocated by primary spectrum holders (PSH's), or proxies assigned to manage a given allocations of spectrum, to temporarily “rent” access to the spectrum held by PSH's to other entities such as, for example, operators of mobile wireless networks, by integrating use of both International Mobile Telecommunication (IMT) bands and non-IMT bands in wireless multi-mode devices (MMD's).
2. Related Art
The last decade and a half has witnessed an explosion in growth in the use of, and requirements for, wireless data communications, particularly by individual users operating, for example, through exclusively-licensed wireless network operators. This growth continues unabated today as the numbers and types of wireless devices employed by individual users to access all manner of wireless networks via various communication paths continue to multiply, increasing demand for available spectrum. As the increase in demand for wireless data access continues, the world is headed toward a global spectrum shortage. There is a finite amount of spectrum that can be tapped to support wireless data communication. Availability of wireless spectrum for the increasing numbers and types of wireless devices is key to the continued use of the spectrum to exchange data, and to continued economic growth.
An availability of ever increasingly-capable wireless data communications has also created in individual users an expectation of a certain quality of service. In short, individual wireless data communication consumers, for example, expect quality wireless data and voice communications to be available anytime and anyplace. If solutions are not found, users of certain MMD's will frustratingly experience increased instances of dropped calls and slow data speeds all while paying higher fees to access the scarce resource that will be the wireless voice and data communication spectrum.
Wireless MMD's are used to provide individual customers virtually instantaneous and continuous wireless access to email, social media, applications and streaming video. These MMD's are currently estimated to use 25 to 125 times the amount of spectrum that was used by earlier generation cellular telephones. Various industry estimates expect growth in global mobile data traffic to double every 1-2 years for the foreseeable future.
Exclusive mobile spectrum licenses carve out to their licensees portions of the available spectrum that are used for wireless data and voice communication. Licensees in any geographic area include government agencies, which sometimes reserve communication spectrum to certain “required” wireless voice and data communications. A non-exhaustive list of these communications users includes broadcast radio and television communications, satellite communications, public safety and emergency services communications, military communications, and certain other commercial communication requirements to include, for example, communications with aircraft for navigation and air traffic control. Licensees in particular geographic areas also include wireless network operators such as, for example, mobile cellular network operators. A cursory review of a breakdown of the licensed spectrum for any particular geographic area reveals that the availability of new spectrum to support assignment of additional exclusive licenses to any particular licensee is nearly exhausted.
A detailed review of the challenges faced by mobile cellular network operators as an example starts with an overview of their operations. Mobile cellular network operators license spectrum bands for their exclusive use within a particular geographic region. These entities then contract with individual customers purchasing or being provided with network-connected MMD's to provide certain levels of service with express or implied guarantees of connectivity, and of communications fidelity at increasing rates of delivery. As mobile cellular network communication traffic continues its dramatic increase, congestion occurs today and the congestion is forecast to rise significantly in coming years in the portions of the spectrum currently licensed to mobile cellular network operators to support wireless voice and data communications.
In the face of current and forecast issues regarding network congestion in their licensed spectrums, wireless network operators have taken to purchasing additional exclusive spectrum licenses in the secondary market from other exclusive licensees (spectrum holders) whose licensed spectrum is underused or otherwise available. Buying additional spectrum licenses allows wireless network operators to build or expand their networks and handle more customer traffic. In fact, in late 2011, one major mobile cellular network operator in the U.S. reached an agreement, subject to regulatory approval, to buy a license for a small swath of wireless communication spectrum (around 20 MHz) from several broadcast cable companies for an amount that was reported to be in excess of three and one half billion dollars.
Efforts are ongoing to optimize wireless data communication to make more effective use of available spectrum. Consider the available spectrum as a pipe with a finite maximum diameter. Ongoing efforts attempt to optimize the flow of data through that pipe, thereby reducing the amount of spectrum used. These efforts include use of compression techniques, video optimization and burst transmissions such that overall data transmission through the pipe is streamlined and optimized, i.e., techniques are implemented to pass larger amounts of data in what appears to be a smaller volume of flow through the pipe. Additional efforts are focused on concepts such as Wi-Fi offload or small cell development to ease the burden on the saturated portions of the spectrum exclusively licensed to mobile cellular network operators. All efforts at making data flow more efficient, thereby improving spectral efficiency, will reap benefits. Regardless of these efforts, however, the pipe will never get any bigger due to the fixed, finite spectrum covered by licenses. The above efforts may delay the inevitable. There will still come a time, however, when currently-licensed portions of the spectrum that support mobile voice and data communications will be overburdened. When this overburdening occurs, a mobile cellular network operator has at its disposal methods, some of which are used today, by which to maintain service across its exclusively-licensed spectrum for all of its individual customer MMD's. Often these methods reduce the quality of service experienced by individual customers. Common techniques include, for example, mobile cellular network operators “throttling” rates at which data may be received by individual customers'MMD's. As with any supply and demand scheme, a wireless network operator can exact a premium from certain of its individual customers according to currently-licensed spectrum for its use to prioritize which individual customers get “throttled” last.